Imaging a neglected transradial, trans-scaphoid volar perilunate fracture dislocation in a skeletally mature adult: a novel constellation.

To cite: Kumar S, Ayachit A, Varman M, et al. BMJ Case Rep Published online: [please include Day Month Year] doi:10.1136/ bcr-2014-208578 DESCRIPTION A well-built 31-year-old man presented with deformity and restricted movements of the left wrist joint. He gave a history of injury due to a fall 8 months earlier, for which he was initially treated with a wrist slab for 3 months. Clinical examination revealed palmar flexion deformity with restricted movements in all directions at the left wrist joint. Neurovascular examination was unremarkable. Plain film radiograph showed diffuse osteopaenia, overlapping of the two carpal rows, distracted fractures of radial styloid process and scaphoid with associated midcarpal volar dislocation (figure 1A, B). CT scan demonstrated a fracture across the waist of scaphoid with volar displacement of the distal scaphoid fracture fragment along with the distal row carpus (figure 2A). The lunate showed mild volar tilt but was adequately aligned with the radial articular surface, while capitate along with distal scaphoid fragment was dislocated volarly (figure 2B). The distal carpal row bones were well aligned with each other and showed maintained distal articulations with the metacarpal heads (figure 2C). Features of midcarpal osteoarthritic changes were also seen (figure 2D). Three-dimensional (3D) CT scan reconstruction demonstrated the maintained alignment between the individual carpi of the proximal and distal carpal rows with fractured proximal fragment of scaphoid remaining with the rest of proximal row carpi and its distal fragment moving anteriorly in concert with the volarly dislocated distal carpal row (figure 3A–C). Perilunate fracture dislocation (PLD) occurs due to high-energy wrist hyperextension trauma and represents a common form of carpal dislocation. Usually, the carpus dislocates dorsally, but in 3% it dislocates volarly. The functional anatomy of the wrist is best explained by Gilula’s concept of three arcs, with the first arc formed by the proximal surfaces of scaphoid, lunate and triquetrum, the second arc formed by their corresponding distal articulating surfaces and the third arc formed by proximal curvature of capitate and hamate. Thus, effectively, the proximal carpal row forms an intercalated system between the radial articular surface and the distal carpal row, while scaphoid forms the stabilising link between the proximal and distal carpal rows. This arrangement of the carpus along with the intrinsic and extrinsic ligaments of the wrist provide stability to the wrist joint and also